1. Field of the Invention
The present invention relates to an vehicle-mounted engine control apparatus provided with an improved microprocessor-initialization means that resets a microprocessor in response to the occurrence of a contingent malfunction, e.g., due to an erroneous operation caused by noise, rapidly performs inspection and initialization, and then restart the microprocessor.
2. Description of the Related Art
In general, in the case where, when a microprocessor malfunction occurs while the engine is running, the microprocessor is reset and then restarted after the inspection of related units, it is required to spend enough time so as to perform a sufficient inspection in consideration of the safety; however, there exists a contradictory demand that the engine interruption time is shortened as much as possible. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-150999) discloses a technology in which applications are divided into a first type application corresponding to a control means that are required to preferentially function upon the activation of a control apparatus and a second type application corresponding to the other control means, and when the control apparatus is activated, the resource setting is performed only for the first type application having higher priority, and the resource setting for the second type application having lower priority is performed after the activation of the first application; a vehicle control apparatus has been provided in which, in the case where an ECU (electronic control unit), which is a main control device for hardware that implements a plurality of applications, is reset and then restarted, the operation interruption time, of specific important functions, due to the restarting processing can be shortened, and eventually, user's sense of discomfort or sense of displeasure due to the functional interruption can be reduced.
In addition, Patent Document 2 (Japanese Patent Application Laid-Open No. 2003-97345) discloses a vehicle electronic control apparatus that includes a CPU (microprocessor) for implementing the control of engine injection, ignition, and throttle and a WD (watchdog timer) circuit for monitoring the operation of the CPU, and in which the WD circuit outputs a reset signal to the CPU in the case
where a WD pulse from the CPU does not reverse in a time the same as or longer than a predetermined time, a storage unit formed of a flip-flop, a counter, or the like is provided in the WD circuit, reset information is stored in the storage unit each time the reset signal is outputted to the CPU, the storage unit is formed of a reset counter for counting the number of resets as the reset information, and when being restarted, the CPU implements fail-safe processing, in the case where the value of the reset counter is the same as or larger than a threshold value.
In contrast, Patent Document 3 (Japanese Patent Application Laid-Open No. 2003-155945) discloses an activation-timing fuel injection control apparatus, for an internal-combustion engine, that includes a means for presuming the startability of the internal-combustion engine; a crank-angle detection means for outputting a crank-angle signal in synchronization with the specific crank-angle position of each cylinder of the internal-combustion engine; a cylinder discrimination means for discriminating the reference crank angle of a specific cylinder; a means for starting concurrent injection of a fuel into all the cylinders before, upon the activation of the engine, the cylinder discrimination has been completed; and a means for sequentially starting separate injection for each cylinder in synchronization with the crank-angle signal immediately after the cylinder discrimination has been completed, and in which provision is made for a means for starting the separate injection immediately after the cylinder discrimination has been completed and concurrently injecting the fuel in a cylinder that is ready to take in the fuel, only in the case where it is presumed that the startability of the internal-combustion engine is lower than a predetermined level, whereby, while ensuring the startability, imperfect combustion upon the activation of the engine can be prevented and the amount of HC emissions upon the activation of the engine can be reduced. In addition, related to the present invention, Patent Document 4 (Japanese Patent Application Laid-Open No. 2004-027976) explains in detail a cylinder discrimination method for determining the fuel injection timing and the ignition timing for a multicylinder vehicle engine by use of a crank angle sensor    [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-150999    (Patent Document 2) Japanese Patent Application Laid-Open No. 2003-097345    [Patent Document 3] Japanese Patent Application Laid-Open No. 2003-155945    (Patent Document 4) Japanese Patent Application Laid-Open No. 2004-027976
In the vehicle control apparatus set forth in Patent Document 1, in the case a single microprocessor controls a plurality of apparatuses that are not directly related to one another, the initialization and the restart are performed in order of priority so that the initialization time and the restart time for a preferential load is shortened; however, there exists a problem that, in the case where a single microprocessor controls a plurality of apparatuses that are tightly related to one another, such a divided restart method cannot be applied.
Moreover, in the vehicle electronic control apparatus set forth in Patent Document 2, by performing the monitoring of microprocessor malfunction through a watchdog timer as well as by utilizing the self-diagnosis function of the microprocessor, the safety is enhanced;
however, the shortening of the initialization time and the restart time upon the occurrence of a malfunction is not described.
Furthermore, in Patent Document 3, asynchronous fuel injection for improving the startability of an engine is described; however, no application is anticipated that does not require activation by an starter motor because, before the engine rotation is decelerated after fuel injection in the engine in a high-speed rotation has temporarily been interrupted, the fuel injection is restarted.